Without knowing the spacing of the dropouts on your bike I'm assuming they are less than the 185mm the new SA 5 speed requires. Easy solutions would be to cold set the rear to the size needed or locate an older hub with a narrow spacing. The older FW hub offers 4 widley spaced gears, the lowest is a granny gear that will take you over most any paved hill. To climb hills, your not looking for more gears, just a wider range and the FW will give you that with nearly the same spacing as your current hub. If your buying a used FW make sure the # of spoke holes match your rims.